户外像素管软质灌注胶的研制与应用

采用脂环族环氧树脂、柔韧性环氧树脂、改性脂环胺类固化剂为主要原料，研制出户外像素管灌注软胶，产品具有耐紫外线辐照、耐冷热冲击、粘接性好等特点。介绍其制备方法、性能及用。     

对鸡头米中提取栲胶的研究

在芡实栲胶提取中初步研究结果表明：在使用65％的乙醇的水溶液，粒度为0．3cm方块，浸提温度选择在55℃，浸出时间选择在2h，乙醇水溶液中的水应使用蒸馏水，加入适量的表面活性剂。浸提液的酸碱性为中性等条件下可得到栲胶9％～13％。     

烟草浸出液防治菜青虫及对蔬菜品质的影响

用四种不同浓度烟草浸出液防治菜青虫，与40％乐果比较。试验结果表明2倍液防治效果最好。杀虫率平均迭87．5％。以清水为对照。采用问接萃取比色法。做出烟碱的标准工作曲线。喷药24、48、72h后采集样品。测定其残留，4种浓度的残留均未检出。同时进行蔬菜生理指数的测定，结果显示喷药后叶绿素的含量显著增多。维生素C含量变化明显。     

Studies on phytosterol oxides. II: Content in some vegetable oils and in French fries prepared in these oils

Hydrogenated rapeseed oil/palm oil blend, sunflower oil and high-oleic sunflower oil, and French fries fried in these oils were assessed for contents of sterol oxidation products. Different oxidation products of phytosterols (7α- and 7β-hydroxy-sito-and campesterol, 7-ketosito- and 7-ketocampesterol, 5α,6α-epoxy-sito- and campesterol, 5β,6β-epoxy-sito-and campesterol, dihydroxysitosterol and dihydroxycampesterol) were identified and quantiated by gas chromatography (GC) and GC-mass spectroscopy. Rapeseed oil/palm oil blend contained 41 ppm total sterol oxides before frying operations. After two days of frying, this level was increased to 60 ppm. Sunflower oil and high-oleic sunflower oil had 40 and 46 ppm sterol oxides, respectively, before frying operations. After two days of frying operations, these levels increased to 57 and 56 ppm, respectively. In addition to campesterol and sitosterol oxidation products, small amounts of 7α- and 7β-hydroxystigmasterol were detected in the oil samples. Total sterol oxides in the lipids of French fries fried at 200°C in rapeseed oil/palm oil blend, sunflower oil, and high-oleic sunflower oil were 32, 37, and 54 ppm, respectively. The levels of total oxidized sterols, calculated per g sample, ranged from 2.4 to 4.0 ppm. In addition to the content of phytosterol oxides, full scan mass spectra of several oxidation products of stigmasterol are reported for the first time. Part of these results were presented at the 86th Annual Meeting of the AOCS, May 7–11, 1995, San Antonio, TX.     

浩伦松碱合剂防治柑桔蚧壳虫的田间应用

通过在3个省份的田间试验充分表明，浩伦松碱合剂是防治柑桔蚧壳虫的良好药剂。推荐使用45％浩伦松碱合剂4500—5625mg／kg的剂量较好，在药后15d对柑桔蚧壳虫的防效为86．95％～89．11％。     

羧甲基纤维素钠/阳离子瓜尔胶共混膜用作药物缓释材料的研究

以可生物降解和生物相容的羧甲基纤维素钠(NaCMC)与阳离子瓜尔胶(GG)为原料,制得系列不同配比的多糖共混膜。以此共混膜作为药物布洛芬的载体,考察了共混比、药物浓度以及pH值对药物释放的影响,并研究了其药物释放机理。结果发现,对布洛芬药物释放影响最大的是介质的pH值,其次是共混膜的共混比例,药物含量在弱碱介质中有一定的影响,在酸性介质中基本无影响。大部分的药物释放n>0.89,为非Fick扩散(骨架溶蚀机制),药物以零级进行释放。共混膜对疏水性药物布洛芬具有较好的缓释性能。     

阳离子香豆胶的合成及结构表征

以3-氯-2-羟丙基三甲基氯化铵(HAT)为阳离子醚化剂,天然香豆胶为原料,异丙醇为分散剂制得季铵盐型阳离子香豆胶。研究了HAT、催化剂NaOH、反应温度和反应时间对合成阳离子香豆胶(CFG)的影响,用凯氏定氮法测定了CFG的取代度。合成CFG的优化实验条件为:m(香豆胶)∶m(异丙醇)∶m(HAT)∶m(NaOH)=1∶(1.6~2)∶(0.15~0.3)(∶4~8),反应温度40~50℃,反应时间2~3 h,制得的产品能满足工业应用要求的黏度及取代度范围(500~800 mPa.s,DS=0.86~1.32)。用FTIR和13CNMR对CFG的结构进行了表征。     

Phase diagrams for oil/methanol/ether mixtures

One-phase transmethylations of vegetable oils with methanol to form methyl esters occur considerably faster than conventional two-phase reactions. Addition of simple ethers is an efficient method for producing a single phase. Ternary phase diagrams have been determined at 23°C for oil/methanol/ether mixtures; these are useful when applying the one-phase method across a wide range of conditions. Soybean, canola, palm, and coconut oils were used in combination with five ethers, namely, tetrahydrofuran (THF), 1,4-dioxane (DO), diethyl ether (DE), diisopropyl ether (DI), andtert-butyl methyl ether (TBM). All five ethers can produce miscibility for all methanol/oil compositions. The ether/methanol volumetric ratios required for miscibility at a methanol/soybean or canola oil volumetric ratio of 0.20 (5.4 molar ratio) at 23°C are: THF, 1.15; DO, 1.60; DE, 1.38 DI, 1.57; and TBM, 1.57. For THF, this results in one-phase mixtures that contain 65 vol% oil. Soybean and canola oil form identical diagrams. Palm oil requires slightly less ether at the lower methanol concentrations, but coconut oil requires considerably less across the whole concentration range. Acid-catalyzed reactions, when performed at the boiling point of the most volatile component, require less ether than predicted from the diagrams.     

吡虫啉在蔬菜中残留量高效液相色谱测定方法

建立了用高效液相色谱法测定出口蔬菜中吡虫啉农药残留量的方法。试样用酸性乙腈提取,C18柱净化,乙酸乙酯洗脱,反相高效液相色谱-紫外检测器测定,检测波长为270nm。方法的最低检测限为0.05mg/kg,0.1～0.5mg/kg水平添加回收率的范围是86.67%～100.33%,相对标准偏差为3.19%～9.95%。     

基于动态硼酸酯键改性黄原胶的性能

基于苯硼酸聚合物可以与存在于黄原胶糖环单元结构中的伯、仲醇羟基通过硼酸酯键形成动态共价微交联结构的性质对黄原胶进行改性。以偶氮二异丁基脒二盐酸盐（AIBA）为引发剂，通过水相自由基聚合，制备了不同共聚比的丙烯酰胺（AM）、N-(3-二甲氨基丙基)丙烯酰胺（DMAPAM）和3-丙烯酰胺基苯硼酸（AMBB）的三元共聚物P(AM-co-DMAPAM-co-AMBB)。通过1H NMR、FTIR、元素分析和光散射对聚合物结构及相对分子质量进行了表征，并对其与黄原胶复配体系的增黏性、流变性、抗老化性及抗干扰性进行了评价。结果表明：P(AM-co-DMAPAM-co-AMBB)与黄原胶复配后对黄原胶溶液具有明显的增黏性，其中苯硼酸单体的摩尔比为1.0 mol%的聚合物对黄原胶溶液的增黏幅度达43.8%，在8074 mg/L的矿化水中增黏幅度高达56.4%，且复配体系具有良好的抗老化降解性，对乙二醇和1,3-丙二醇具有较强的抗干扰性。